WATCH - girl's reaction to being told she's being adopted

The office manager at her school is a woman named Jackie Alexander. She's friends with Tannah's foster parents, and got to give her the good news at last Monday.

A video of the moment Tannah found out is all over Facebook, because it's just pure joy.

A security camera at the school caught her reaction. She was so excited, she literally JUMPED into Jackie's arms and wouldn't let go.

Jackie called Tannah's foster parents to get permission before she posted the video online. It happened one day after the shooting in Vegas. And she wanted to remind people there are still GOOD moments in life that we can all appreciate.

By the way, Tannah's foster parents aren't just adopting HER. They're also adopting her 6-year-old brother, AND her 2-year-old sister.